Method of packaging packs or articles with a heat-shrinking material

ABSTRACT

A method of packaging packs or other articles with a heatshrinking material is disclosed whereby a tear-tab is automatically formed protruding sideways from each package. The method comprises wrapping a pack or article with a sheet of overwrap of synthetic resin film which tends to shrink when heated. The open sides of the overwrap are heat-sealed thereby hermetically sealing the wrap. At the same time, a laminate of the front and rear part of the overwrap is formed by fusion with heat at a suitable portion on a side of the overwrap. Then, the overwrap is heated thereby allowing it to shrink in such manner that the entire overwrap excepting the laminated portion shrinks close to the outer surface of the pack or article and that the inner edge of the laminated portion is supported by the outer surface of the pack or article in the direction at a right angle thereto thereby allowing the laminated part to extend outwardly.

United States Patent Fujio Feb. 15, 1972 [72] Inventor: Masaaki Fujlo,3-15-8 Aoyamadai, Suita,

Japan [22] Filed: Mar. 5, 1970 [21] Appl. No.: 16,896

[52] US. Cl ..53/l4, 53/30, 229/51 TS, 229/66 [51] Int. Cl. ..B65b61/18, B65d 65/32 [58] Field of Search ..53/14, 30; 93/1 TS; 229/51 TS,229/51 S, 51 AS, 66, 85, 86

[56] References Cited UNITED STATES PATENTS 3,371,462 3/1968 Nordkvistet al ..53/30 X 3,497,131 2/1960 Tracy ....229/66 2,851,212 9/1958Parmer ....229/66 3,429,495 2/1969 McClosky ....229/66 X 6/1970 Dreyfuset al ..229/66 X Primary ExaminerTheron E. Condon AssistantExaminer-Neil Abrams Attorney-Jacobi, Lilling and Siegel [5 7] ABSTRACTA method of packaging packs or other articles with a heatshrinkingmaterial is disclosed whereby a tear-tab is automatically formedprotruding sideways from each package. The method comprises wrapping apack or article with a sheet of overwrap of synthetic resin film whichtends to shrink when heated. The open sides of the overwrap areheat-sealed thereby hermetically sealing the wrap. At the same time, alaminate of the front and rear part of the overwrap is formed by fusionwith heat at a suitable portion on a side of the overwrap. Then, theoverwrap is heated thereby allowing it to shrink in such manner that theentire overwrap excepting the laminated portion shrinks close to theouter surface of the pack or article and that the inner edge of thelaminated portion is supported by the outer surface of the pack orarticle in the direction at a right angle thereto thereby allowing thelaminated part to extend outwardly.

7 Claims, 8 Drawing Figures PATENTEurzm m2 3.641.732

sum 1 or 2 $104 oak-.4, $2., i 7 1 ATTORNEY PATENTEDFEB 15 mm 3.641 J32SHEET 2 0F 2 FIG.6

INVENTOR ATTORNEY METHOD OF PACKAGING PACKS OF ARTICLES WITH AHEAT-SHRINKING MATERIAL This invention relates, in a broad sense, to amethod of packaging with the use of a heat-shrinking material such asthe synthetic resin film that tends to shrink when heated. Specificallythe invention relates to a method of packaging products with aheat-shrinking material by heating the material thereby allowing it toshrink into intimate contact with the contents while projecting a partof the material automatically to form tear tabs which enable theresulting package to be torn open with little effort.

Packages of paperboard cartons, bottles and other containers, and alsounpackaged products themselves, overwrapped with heat-shrinkingsynthetic resin film for both additional protective and decorativeeffects have a common disadvantage in that the overwraps stick soclosely to the underlying surfaces and are in such tension that they aredifficult to tear when the packages must be torn open.

In an effort to facilitate the tearing of the overwraps, it has beenproposed to form perforations along all sides or peripheral margins ofthe overwraps. The advantage thus derived, however, is offset by thepoor appearance presented by the perforations enlarged by the thermalcontraction of the overwraps and by the ingress of dirt and otherforeign matter into the packages through the fairly enlarged holes.

Another approach to the problem has been to perform a projecting teartab or tabs on part of an overwrap. It requires additional labor andcomplicates the material cutting, with decreased yield. Moreover, wherethe thickness of the overwrapping film is not thick enough, the tabstend to be broken or torn off to a disadvantage.

This invention concerns a method of packaging with a heatshrinkingmaterial whereby tough and yet ready-to-tear tabs are formed bythemselves upon thermal contraction of the overwrap, despite the factthat the overwrap material is not cut into the shape and size with anypreformed tab.

The invention will now be described in further detail with reference tothe accompanying drawings showing embodiments thereof. In the drawings:

FIG. 1 is a perspective view ofa sheet of overwrap material folded intwo to sandwich an article to be packaged;

FIG. 2 is a perspective view, partly broken away, of the overwrap sealedat three sides thereby enclosing the article therein;

FIG. 3 is a perspective view, partly broken away, of a package formed inaccordance with the present invention;

FIG. 4 is a perspective view of the overwrap of FIG. 3 as torn open;

FIGS. 5 and 6 show another embodiment of the invention, FIG. 5 being aperspective view, partly broken away, of the overwrap sealed at threesides thereby enclosing the article therein, and FIG. 6 being aperspective view, partly broken away, of a package formed in accordancewith the invention; and

FIGS. 7 and 8 are perspective views, partly broken away, of overwraps inthe form of bags in which articles to be packaged are enveloped.

As shown in FIG. 1, a rectangular sheet of overwrap 1 consisting of asynthetic resin film having a heat-shrinking tendency is folded in twolayers to sandwich an item to be packaged such as a pack 2. Next, thethree open sides of the overwrap l are heat sealed as at 3 by athree-side sealer, excess film is trimmed off, and the front part 4 andthe rear part 5 of the overwrap 1 are fused together at a desirablecorner to form a triangular tab 6. Then, the overwrap l is heated toshrink into close contact with the outer surface of the pack 2.

With the contraction of the overwrap l, the tab 6 is drawn close to thepack 2 until its inner edge 6 contacts the corner of the pack 2. Formedof the front part 4 and the rear part 5 fused together, the tab 6 itselfshrinks little as compared with the rest of the overwrap 1. For thisreason, when the overwrap 1 has stuck completely to the surface of thepack 2, the tab 6 remains protruded outwardly from the pack 2 at a rightangle thereto, with the inner edge 6' supported by the corner of thepack 2.

The tab 6 may be provided in a suitable number, shape and location. Forexample, such tabs may be formed at two or more corners of the overwrap1, or a single tab may be provided at a side of the overwrap. In thelatter case, the rectangular sheet of overwrap of FIG. 1 wraps the pack2 and the wrap is heat sealed at three sides, and then the front part 4and the rear part 5 are fused together at a part intermediate of oneside 7 of the overwrap l to form a square laminate ofa desirable widthand depth (FIG. 5). On both sides of this laminate there are formed twoparallel slits 8 leaving laminated edges 9 of narrow width alongside theslits and thus defining a tab 6 therebetween. The overwrap l is thenheated and allowed to shrink, when the laminated edges 9 on the outersides of the slits 8 are pulled in the opposite directions away fromeach other, until they are aligned with the sealed part 3 on the side 7of the overwrap 1 and in close contact with the corresponding side ofthe pack 2, as shown in FIG. 6, thereby leaving the tab 6 supported atthe inner edge 6' by the side of the pack 2 and protruding as a while inthe direction at a right angle thereto.

It will be seen from the foregoing that, in accordance with the presentinvention, the overwrap 1 is allowed to contract by heating so that theentire wrap excepting the tab 6 shrinks into intimate contact with thepack 2 or other particle to be packaged, when the tab 6 is automaticallyformed as protruding sidewise from a side of the overwrap, as shown inFIGS. 3 and 4.

As the tab 6 thus formed is pulled upward or downward with some extraforce, the overwrap l is torn open in two, as shown for example in FIG.4, with two parallel tear lines 10 extending from the root of the taband ending in the diagonally opposite corner.

Thus, according to the present invention, the tab 6 is automaticallyformed on thermal contraction of the overwrap l and there is no need ofpreforming anything like tab 6. This feature makes the packagingoperation simple and efficient, and also economical because the materialloss is reduced to a minimum. Moreover, the tab 6 is tough since it istwice as thick as the overwrap l itself. With these and other features,the invention proves very advantageous in practice.

Where necessary, perforations 11 may be formed over some lengths inopposite directions from the root of the tab 6 for the convenience intearing the overwrap 1 by the tab 6.

In such a case the perforations 11 may be very short because they haveto be simply long enough to direct the tear of the overwrap 1.Accordingly the amount of dirt or foreign matter that gains entranceinto the package through the perforations 11 is very small and istotally negligible for practical purpose.

Although the present invention has so far been described in conjunctionwith the embodiments thereof in which the overwrap l employed is formedof a sheet folded in two, the overwrap 1 may also be in the form of abag open on one side 1 only, as shown in FIGS. 7 and 8. Where the latteris preferred, a tab 6 is preformed in two ways. In one method, asillustrated in FIG. 7, the front part 4 and the rear part5 of thebag-shaped overwrap 1 are joined together by fusion at a corner of theside opposite to the opening 1 to a triangular laminate. In the othermethod, as shown in FIG. 8, a square laminate of a desired width anddepth is formed intermediate on one side of the bag-shaped overwrap l,and two parallel slits 8 are provided, leaving narrow laminated edges 9adjacent both sides of the laminate, so that the laminate definedbetween the two slits 8 can serve as a tab 6.

Here again, if necessary, the tab 6 may be provided with two parallellines of perforations 11 from both ends of the root thereof.

Such a bag-shaped overwrap 1, which has contained a pack or article 2 tobe packaged, is sealed at the opening to the state of a hermeticallysealed bag that contains the pack or article like the first or secondembodiment of the present invention above described in the state shownin FIG. 2 or FIG. 5 of the accompanying drawings, respectively. Next,the sealed overwrap l is heated in the same manner as with either of theembodiments already described, whereby a package having the tabprotruding sidewise and outwardly as shown in FIG. 3 or FIG. 6 isobtained.

lclaim:

l. A method of packaging articles with a heat-shrinking material wherebya tear tab is automatically formed protruding sideways and substantiallyperpendicular from the package, which comprises the steps of wrapping anarticle in at least one sheet of wrapping material of a synthetic resinfilm which tends to shrink when heated, heat sealing the open sides ofthe wrapping material and forming a laminating tear tab of the front andrear parts of the wrapping material by fusion with said heat at asuitable portion on the peripheral surface of the wrapping materialthereby hermetically sealing said article, and heating the wrappingmaterial thereby allowing it to shrink in such a manner that the entirewrapping material except said laminated tear tab portion shrinks closeto the outer surface of the article and that the inner edge of saidlaminated tear tab portion is supported by the outer surface of thearticle in a direction substantially at a right angle thereto, therebyallowing the laminated tear tab portion to extend outwardly.

2. A method of packaging articles with a heat-shrinking material wherebya tear tab is automatically formed protruding sidewise and substantiallyperpendicular from the package, which comprises laminating by fusion thefront and rear parts of a bag-shaped overwrap of a heat-shrinkingsynthetic resin film which tends to shrink on heating into intimatecontact with the outer surface of an article thereby packaging the same,forming along an edge of the overwrap, a

laminated tear tab portion of the front and rear parts of said bag byfusion with said heat, slitting both side edges of the laminated teartab portion so as to define said laminated tear tab portion from therest of the bag-shaped overwrap, introducing an article to be packagedinto the bag-shaped overwrap, heat sealing the open end of the bag, andheating the overwrap thereby causing shrinkage, in such a manner thatthe entire overwrap excepting said preformed laminated tear tab portionshrinks close to the outer surface of the article whereby the inner edgeof said laminated tear tab portion is supported by the outer surface ofthe article in a direction substantially at a right angle thereto,thereby allowing the laminated tear tab portion to extend outwardly.

3. The method according to claim 1, wherein slits are formed on sides ofsaid laminated tear tab portion leaving narrow laminated edges adjacentsaid laminated tear tab portion.

4. The method according to claim 1, wherein said laminated tear tabportion is formed at a corner of the wrapping material so as to form atriangular shaped tear tab.

5. The method according to claim 2, wherein said laminated tear tabportion is formed at a corner of the wrapping material so as to form atriangular shaped tear tab.

6. The method according to claim 1, including the step of forming theperforations for a short length from the root of said laminated tear taband extending outwardly therefrom so as to direct and facilitate tearingopen the package.

7. The method according to claim 2, including the step of forming theperforations for a short length from the root of said laminated tear taband extending outwardly therefrom so as to direct and facilitate tearingopen the package.

1. A method of packaging articles with a heat-shrinking material wherebya tear tab is automatically formed protruding sideways and substantiallyperpendicular from the package, which comprises the steps of wrapping anarticle in at least one sheet of wrapping material of a synthetic resinfilm which tends to shrink when heated, heat sealing the open sides ofthe wrapping material and forming a laminating tear tab of the front andrear parts of the wrapping material by fusion with said heat at asuitable portion on the peripheral surface of the wrapping materialthereby hermetically sealing said article, and heating the wrappingmaterial thereby allowing it to shrink in such a manner that the entirewrapping material except said laminated tear tab portion shrinks closeto the outer surface of the article and that the inner edge of saidlaminated tear tab portion is supported by the outer surface of thearticle in a direction substantially at a right angle thereto, therebyallowing the laminated tear tab portion to extend outwardly.
 2. A methodof packaging articles with a heat-shrinking material whereby a tear tabis automatically formed protruding sidewise and substantiallyperpendicular from the package, which comprises laminating by fusion thefront and rear parts of a bag-shaped overwrap of a heat-shrinkingsynthetic resin film which tends to shrink on heating into intimatecontact with the outer surface of an article thereby packaging the same,forming along an edge of the overwrap, a laminated tear tab portion ofthe front and rear parts of said bag by fusion with said heat, slittingboth side edges of the laminated tear tab portion so as to define saidlaminated tear tab portion from the rest of the bag-shaped overwrap,introducing an article to be packaged into the bag-shaped overwrap, heatsealing the open end of the bag, and heating the overwrap therebycausing shrinkage, in such a manner that The entire overwrap exceptingsaid preformed laminated tear tab portion shrinks close to the outersurface of the article whereby the inner edge of said laminated tear tabportion is supported by the outer surface of the article in a directionsubstantially at a right angle thereto, thereby allowing the laminatedtear tab portion to extend outwardly.
 3. The method according to claim1, wherein slits are formed on sides of said laminated tear tab portionleaving narrow laminated edges adjacent said laminated tear tab portion.4. The method according to claim 1, wherein said laminated tear tabportion is formed at a corner of the wrapping material so as to form atriangular shaped tear tab.
 5. The method according to claim 2, whereinsaid laminated tear tab portion is formed at a corner of the wrappingmaterial so as to form a triangular shaped tear tab.
 6. The methodaccording to claim 1, including the step of forming the perforations fora short length from the root of said laminated tear tab and extendingoutwardly therefrom so as to direct and facilitate tearing open thepackage.
 7. The method according to claim 2, including the step offorming the perforations for a short length from the root of saidlaminated tear tab and extending outwardly therefrom so as to direct andfacilitate tearing open the package.